1. Field of the Invention
This invention relates to a paper feeding apparatus in a printer, and more specifically, a paper feeding apparatus including a paper guiding member disposed on a paper feeding path in a printer.
2. Description of the Related Art
A paper guiding apparatus is installed on a paper path in a printer. A cut sheet of paper fed from a cassette passes through the paper path and is loaded into a main body of the printer. Typically, the paper guiding apparatus includes a feeding roller rotating by a motor and feeding the cut sheet into the main body of the printer while rotating, a friction roller disposed to push against the feeding roller, and a base frame supporting said sheet of paper fed by feeding roller and disposed between the main body and the feeding roller to guide the cut sheet of paper from the feeding roller to the main body of the printer. The cut sheet of paper introduced between the friction roller and the feeding roller is fed by rotation power of the feeding roller and friction power of the friction roller while the base frame supports the sheet of paper fed out from the feeding roller.
The paper guiding apparatus, however, can not continue to feed the cut sheet of paper when one end of the cut sheet is curled and caught by a component of the base frame or the roller while being fed. Ink injected from an ink cartridge can not be properly sprayed on the cut sheet of paper, and this causes poor printing quality.
A conventional ink-jet printer is shown in FIGS. 1 and 2. The printer performs a printing job in such a manner that the ink is sprayed on a cut sheet of paper P while the cut sheet is fed in the direction of arrow A and fed into a base frame 6 by a feed roller 4 and a friction roller 5. An ink cartridge 3 reciprocates along a guide bar 2 installed in a printing area of a printer body 1.
Feed roller 4 protrudes upwardly through a rectangular hole 7 formed on base frame 6 and comes in contact with friction roller 5. Friction roller 5 is rotatably installed at one end of a friction holder 8 and disposed to push against feed roller 4. A nozzle 3a is formed at a bottom side of ink cartridge 3, and the ink injected through nozzle 3a is sprayed on the cut sheet which is fed out from feed roller and supported by a base frame 6. A deflector guide 9 is installed to guide the supply of sheets of paper contained in a cassette.
FIGS. 3A and 3B are top views of a feed roller and a base frame, respectively. In the event that cut sheets of paper are continuously fed into the conventional ink jet printer under a condition that an front end of the cut sheet is curled, that the front end of the cut sheet is not properly supplied through the paper feeding path, and that the cut sheet is caught into hole 7 of base frame 6. The ink can not be properly sprayed on the sheet of paper.
The entire area of the base frame 6 includes a plurality of holes 7 to allow the feed roller to protrude through the hole 7. However, feed roller 4 is disposed to be too close to nozzle 3a of ink cartridge 3 when hole 7 is entirely opened to the sheet of paper. This results in an uneven gap between nozzle 3a and the cut sheet of paper P and causes a deteriorated print in quality.
It is an object of the present invention to provide an improved paper feeding apparatus suitable to guide a sheet of paper passing through a paper path in a straight manner.
It is another object of the present invention to provide a paper feeding apparatus suitable to prevent paper jam when a front end of a cut sheet of paper is curled and fed into a feeding path.
It is yet another object to provide a paper feeding apparatus able to achieve high print quality by suppressing a gap between the nozzle of the ink cartridge and a printable side of the paper.
It is still another object to provide a paper feeding apparatus able to uniformly maintain the high quality of printing operations.
It is a further object to provide a paper feeding apparatus able to perform a printing operation without any deterioration of print quality.
These and other objects may be achieved by providing a paper feeding apparatus including a feed roller rotating by an axle connected to a motor, a friction roller disposed to push against the feed roller and rotating by friction while pushing against the feed roller, a base frame disposed on one output of the friction roller and the feeding roller to support the sheet of paper, rectangular holes formed on the base frame, a plurality of paper guide ribs formed on one side of the rectangular hole of the base frame and protruding from the one side and being extended toward the other side of the rectangular hole, and a plurality of rib receiving grooves formed on a feed roller and corresponding to the paper guide ribs. The ribs are disposed on the respective rib receiving grooves when the feed roller protrudes through the rectangular hole. By inserting the ribs into the grooves, the base frame is level with a top portion of the feed roller and guides the cut sheet in the straight manner from feed roller to the base frame, maintains the same level of the front end of cut sheet fed out from the feed roller, and supports the cut sheet to be located closer to the nozzle.